Speciesspecific acoustic behavior will be studied from the point of view of auditory neurophysiology and behavior genetics. The ability of female crickets to discriminate conspecific mating calls from hetereospecific calls will be tested under natural and laboratory test situations. Hybridization between species of dissimilar calling types has produced F-1 and backcross hybrids. Attempts at correlating genotype with acoustic discrimination behavior will continue, particularly with the aim of determining whether a common set of genes controls species specidific acoustic behavior in both males and females. Thus far there is no information for any species linking genetics and acoustic behavior. Studies thus far have indicated that female crickets are highly sensitive to their own mating calls. Attempts to test the sensitivity of the acoustic system will be made quantitative by employing electronically generated artificial mating calls. The aim is to identify species "typical" trigger features, or cues, that release positive phonotaxic behavior on the part of responding females. This allows us to identify the presence of behavioral filters that undoubtedly have correlates in the acoustic nervous pathways. These behavioral studies are intended to precede a detailed neural analysis of the auditory pathways in the nervous system. These studies will be conducted at the level of single, identified interneurons in the auditory CNS; special attention will be given to sensitivity to such neurons to the temporal pattern of acoustic stimuli. Our ultimate goal is to determine whether or not there exist speciesspecific neural filters in auditory pathways.